In practical terms: think of it as a circuit breaker, not a judge. The model speaks freely upstream; downstream, this mechanism checks whether each output remains within a bounded distance of verified facts under a fixed rule. If it crosses the threshold, it’s excluded. If none survive, the system abstains instead of guessing. The point isn’t semantic authority or “truth,” it’s that the decision process itself is deterministic, inspectable, and identical every time you run it with the same inputs.